Cotyledon test for major gene resistance to white pine blister rust in sugar pine

1980 ◽  
Vol 58 (17) ◽  
pp. 1912-1914 ◽  
Author(s):  
Bohun B. Kinloch Jr. ◽  
Mardi Comstock
Keyword(s):  
Major Gene ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Blister Rust ◽  
Pine Seedlings ◽  
Major Gene Resistance ◽  
Sugar Pine ◽  
Time Required ◽  
Resistant Genotypes

Major gene resistance (hypersensitivity) to white pine blister rust can be detected on cotyledons of inoculated sugar pine seedlings shortly after germination. The cotyledon test reduces the time required for evaluating resistant genotypes from a few years to a few weeks.

scholarly journals Evidence of Cytoplasmic Inheritance of Virulence in Cronartium ribicola to Major Gene Resistance in Sugar Pine

1999 ◽  
Vol 89 (3) ◽  
pp. 192-196 ◽  
Author(s):  
Bohun B. Kinloch ◽  
Gayle E. Dupper
Keyword(s):  
Infection Type ◽  
Major Gene ◽  
Nuclear Gene ◽  
Cronartium Ribicola ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Mendelian Segregation ◽  
Blister Rust ◽  
Major Gene Resistance ◽  
Sugar Pine

Tests for Mendelian segregation of virulence and avirulence in Cronartium ribicola, causal agent of white pine blister rust, to a major gene (R) for resistance in sugar pine were made using haploid basidiospore progenies from single diploid telia as inoculum on resistant genotypes. The telia were sampled from a small deme in the Siskyou Mountains of northern California, where a few mature sugar pines known to be Rr genotypes had become infected after withstanding the chronic blister rust epidemic for several decades and where intermediate frequencies of virulence in the ambient basidiospore population were subsequently measured. Infection type on inoculated seedlings with R was qualitative: all progenies of 81 single telia tested over 3 different years were either virulent (compatible) or avirulent (inducing hypersensitive necrosis), never a mixture of both reactions. The complete absence of heterozygotes in the telia population is strong evidence that virulence is not controlled by a nuclear gene. The data are consistent with earlier tests showing that basidiospore inoculum derived from aeciospores isolated from infected Rr trees produced mostly (>90%) virulent reactions on R— seedlings. The evidence indicates that transmission of virulence is uniparental via the cytoplasm of aeciospores. Exchange of spermatia between haploid thalli does not appear to be involved.

Restricted distribution of a virulent race of the white pine blister rust pathogen in the western United States

1987 ◽  
Vol 17 (5) ◽  
pp. 448-451 ◽  
Author(s):  
Bohun B. Kinloch Jr. ◽  
Gayle E. Dupper
Keyword(s):  
United States ◽  
Major Gene ◽  
Resistance Mechanisms ◽  
Western United States ◽  
White Pine Blister Rust ◽  
Blister Rust ◽  
Rate Of Spread ◽  
Major Gene Resistance ◽  
Sugar Pine ◽  
Resistant Genotypes

A race of Cronartiumribicola virulent to a major gene for resistance to blister rust in sugar pine appears to be limited to the site where first discovered on resistant genotypes in 1978. It was not detected in inocula surveyed extensively throughout a large part of the range of blister rust in the western United States and detected only rarely in inocula surrounding the discovery site. Nor was it found attacking resistant genotypes in other test plantings either nearby or remote from this site. Rate of spread of the virulent race from the discovery site was too slow to be measured during 6 years of observation. These results imply that major gene resistance may be usable for at least one rotation of improved planting stock, while other resistance mechanisms are being developed.

scholarly journals Influence of Host Resistance on the Genetic Structure of the White Pine Blister Rust Fungus in the Western United States

2008 ◽  
Vol 98 (4) ◽  
pp. 413-420 ◽  
Author(s):  
B. A. Richardson ◽  
N. B. Klopfenstein ◽  
P. J. Zambino ◽  
G. I. McDonald ◽  
B. W. Geils ◽  
...  
Keyword(s):  
United States ◽  
Genetic Structure ◽  
North America ◽  
Major Gene ◽  
Western United States ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Blister Rust ◽  
Major Gene Resistance ◽  
Sugar Pine

Cronartium ribicola, the causal agent of white pine blister rust, has been devastating to five-needled white pines in North America since its introduction nearly a century ago. However, dynamic and complex interactions occur among C. ribicola, five-needled white pines, and the environment. To examine potential evolutionary influences on genetic structure and diversity of C. ribicola in western United States, population genetic analyses of C. ribicola were conducted using amplified fragment length polymorphism (AFLP) molecular markers. The fungus was sampled at six sites. Collections for two of the six sites were from separate plantings of resistant-selected western white pine and sugar pine. Heterozygosity based on polymorphic loci among populations ranged from 0.28 to 0.40, with resistant-selected plantations at the extremes. Genetic differentiation was also highest between these two populations. Principal coordinates analysis and Bayesian assignment placed most isolates that are putative carriers of virulence to major-gene resistance into a discernable cluster, while other isolates showed no clustering by site or host species. These results indicate that C. ribicola in western North America is not genetically uniform, despite its presumed single site of introduction and relatively brief residence. Moreover, major-gene resistance appears to have imposed strong selection on the rust, resulting in reduced genetic diversity. In contrast, no evidence of selection was observed in C. ribicola from hosts that exhibit only multigenic resistance.

scholarly journals Genetic resistance to white pine blister rust in limber pine (Pinus flexilis): major gene resistance in a northern population

2016 ◽  
Vol 46 (9) ◽  
pp. 1173-1178 ◽  
Author(s):  
Richard A. Sniezko ◽  
Robert Danchok ◽  
Douglas P. Savin ◽  
Jun-Jun Liu ◽  
Angelia Kegley
Keyword(s):  
Major Gene ◽  
Genetic Resistance ◽  
The United States ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Pinus Flexilis ◽  
Limber Pine ◽  
Blister Rust ◽  
Major Gene Resistance ◽  
The Status

Limber pine, Pinus flexilis E. James, a wide-ranging tree species in western North America, is highly susceptible to white pine blister rust (WPBR), caused by the non-native fungal pathogen Cronartium ribicola J.C. Fisch. The Canadian populations in particular have been heavily impacted, and in 2014, limber pine was designated endangered in Canada by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Little is known about genetic resistance to WPBR in limber pine, but major gene resistance (MGR) has been characterized in some populations in the United States. This study examines resistance in seedling families from 13 parent trees from British Columbia, Alberta, and Oregon, representing the northern- and northwestern-most populations. Most families were susceptible, with 100% of the seedlings cankered, but one family from Alberta segregated 1:1 for cankered and canker free. This is the first report of (a) MGR in Canada of any of the four species of five-needle pines native to Canada and (b) any resistance in limber pine in Canadian populations and is the northernmost known incidence of putative R-gene resistance in a natural stand of any five-needle pine species. Many of the Canadian selections were from stands with high incidence of WPBR infection, and their high susceptibility in this trial suggests that further infection and mortality is likely in the Canadian populations.

Saturation mapping of a major gene for resistance to white pine blister rust in sugar pine

1998 ◽  
Vol 97 (8) ◽  
pp. 1355-1360 ◽  
Author(s):  
D. M. Harkins ◽  
◽  
P. A. Skaggs ◽  
A. D. Mix ◽  
G. E. Dupper ◽  
...  
Keyword(s):  
Major Gene ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Blister Rust ◽  
Sugar Pine ◽  
Saturation Mapping

Comparative association mapping reveals conservation of major gene resistance to white pine blister rust in southwestern white pine (Pinus strobiformis) and limber pine (P. flexilis)

2021 ◽  
Author(s):  
Jun-Jun Liu ◽  
Anna W Schoettle ◽  
Richard Sniezko ◽  
Kristen M Waring ◽  
Holly Williams ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Quantitative Resistance ◽  
Major Gene ◽  
Snp Markers ◽  
Genomic Diversity ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Limber Pine ◽  
Blister Rust ◽  
Major Gene Resistance

All native North American white pines are highly susceptible to white pine blister rust (WPBR) caused by Cronartium ribicola. Understanding genomic diversity and molecular mechanisms underlying genetic resistance to WPBR remains one of the great challenges in improvement of white pines. To compare major gene resistance (MGR) present in two species, southwestern white pine (Pinus strobiformis) Cr3 and limber pine (P. flexilis) Cr4, we performed association analyses of Cr3-controlled resistant traits using SNP assays designed with Cr4-linked polymorphic genes. We found that ~ 70% of P. flexilis SNPs were transferable to P. strobiformis. Furthermore, several Cr4-linked SNPs were significantly associated with the Cr3-controlled traits in P. strobiformis families. The most significantly associated SNP (M326511_1126R) almost co-localized with Cr4 on the Pinus consensus linkage group 8 (LG-8), suggesting that Cr3 and Cr4 might be the same R locus, or have localizations very close to each other in the syntenic region of the P. strobiformis and P. flexilis genomes. M326511_1126R was identified as a non-synonymous SNP, causing amino acid change (Val376Ile) in a putative pectin acetylesterase (PAE), with coding sequences identical between the two species. Moreover, top Cr3-associated SNPs were further developed as TaqMan genotyping assays, suggesting their usefulness as marker-assisted selection (MAS) tools to distinguish genotypes between quantitative resistance (QR) and MGR. This work demonstrates the successful transferability of SNP markers between two closely related white pine species in the hybrid zone, and the possibility for deployment of MAS tools to facilitate long-term WPBR management in P. strobiformis breeding and conservation.

scholarly journals Use of triadimefon to control white pine blister rust

1996 ◽  
Vol 72 (6) ◽  
pp. 637-638 ◽  
Author(s):  
Jean A. Bérubé
Keyword(s):  
Cronartium Ribicola ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Growth Season ◽  
Effective Protection ◽  
Rust Infection ◽  
Blister Rust ◽  
Pine Seedlings ◽  
Second Growth ◽  
Bare Root

White pine seedlings were treated with triadimefon two weeks prior to natural inoculation with Cronartium ribicola and were observed for two growth seasons. During the second growth season in the greenhouse the incidence of blister rust symptoms was 70.8% for the untreated controls, whereas only 3.8% of the treated seedlings showed symptoms of blister rust. Triadimefon offers effective protection against white pine blister rust infection and would enable the production of bare root seedlings in areas prone to blister rust infection.

scholarly journals Genetic Specificity in the White Pine-Blister Rust Pathosystem

2002 ◽  
Vol 92 (3) ◽  
pp. 278-280 ◽  
Author(s):  
Bohun B. Kinloch ◽  
Gayle E. Dupper
Keyword(s):  
North America ◽  
Great Basin ◽  
Single Gene ◽  
Low Frequency ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Mendelian Segregation ◽  
Blister Rust ◽  
Sugar Pine ◽  
Bristlecone Pine

Four of eight white pine species native to western North America surveyed for resistance to white pine blister rust by artificial inoculation showed classical hypersensitive reactions (HR) at frequencies ranging from very low to moderate. Mendelian segregation, indicating a single dominant allele for resistance (Cr3), was observed in southwestern white pine (Pinus strobiformis), as it was previously in sugar pine (P. lambertiana, Cr1) and western white pine (P. monticola, Cr2). HR was present at a relatively high frequency (19%) in one of five bulk seed lot sources of limber pine (P. flexilis), and was also presumed to be conditioned by a single gene locus, by analogy with the other three species. HR was not found in whitebark pine (P. albcaulis), Mexican white pine (P. ayacahuite), foxtail pine (P. balfouriana), or Great Basin bristlecone pine (P. longaeva), but population and sample sizes in these species may have been below the level of detection of alleles in low frequency. When challenged by (haploid) inocula from specific locations known to harbor virulence to Cr1 or Cr2, genotypes carrying these alleles and Cr3 reacted differentially, such that inoculum virulent to Cr1 was avirulent to Cr2, and inoculum virulent to Cr2 was avirulent to Cr1. Neither of these two inocula was capable of neutralizing Cr3. Although blister rust traditionally is considered an exotic disease in North America, these results, typical of classic gene-for-gene interactions, suggest that genetic memory of similar encounters in past epochs has been retained in this pathosystem.

White pine blister rust: hypersensitive resistance in sugar pine

1977 ◽  
Vol 55 (9) ◽  
pp. 1148-1155 ◽  
Author(s):  
Bohun B. Kinloch Jr. ◽  
Julia L. Littlefield
Keyword(s):  
Hypersensitive Response ◽  
Artificial Inoculation ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Hypersensitive Resistance ◽  
Pale Yellow ◽  
Blister Rust ◽  
Sugar Pine ◽  
Sib Families

Resistance to white pine blister rust in sugar pine is simply inherited and can be identified by distinct needle spot morphs. After artificial inoculation at 2 years of age, seedlings from selfed and full-sib families developed either 'fleck' spots, characterized by a pale, yellow margin with a necrotic fleck in the center, or they developed typical yellow or red spots (or both). Seedlings segregated for needle spot reaction in monohybrid ratios with fleck dominant. Mycelium in secondary needle tissues of fleck spots, in contrast to yellow and red spots, was relatively sparse and confined by dense tannin deposits. Bark infection and mortality was heavy on seedlings with yellow and red spots. On seedlings with fleck spots, no bark symptoms developed from secondary needle infection but small, abortive cankers did develop on some of these seedlings as a result of primary needle infection. These atypical cankers did not sporulate or spread extensively, and had healed by the 2nd year after inoculation. The gene responsible for the fleck reaction thus elicits a hypersensitive response in secondary needles and, apparently, in bark tissues as well.

scholarly journals Genetic mapping of Pinus flexilis major gene (Cr4) for resistance to white pine blister rust using transcriptome-based SNP genotyping

BMC Genomics ◽  
2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Jun-Jun Liu ◽  
Anna W. Schoettle ◽  
Richard A. Sniezko ◽  
Rona N. Sturrock ◽  
Arezoo Zamany ◽  
...  
Keyword(s):  
Genetic Mapping ◽  
Major Gene ◽  
Snp Genotyping ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Pinus Flexilis ◽  
Blister Rust
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